Dynamic tasklist changes sometimes fail to persist

java.lang.IllegalArgumentException: interface com.atlassian.cache.Cache is not visible from class loader

2009-02-15 19:40:11,395 WARN [TP-Processor5] [atlassian.confluence.cache.TransactionalCacheFactory] proxyCacheWithUpdateLogging Could not create logging advised cache
– url: /plugins/servlet/tasklist | userName: pdzwart | referer: http://extranet.atlassian.com/display/~pdzwart/20090216
java.lang.IllegalArgumentException: interface com.atlassian.cache.Cache is not visible from class loader
at java.lang.reflect.Proxy.getProxyClass(Proxy.java:353)
at java.lang.reflect.Proxy.newProxyInstance(Proxy.java:581)
at org.springframework.aop.framework.JdkDynamicAopProxy.getProxy(JdkDynamicAopProxy.java:117)
at org.springframework.aop.framework.JdkDynamicAopProxy.getProxy(JdkDynamicAopProxy.java:108)
at org.springframework.aop.framework.ProxyFactory.getProxy(ProxyFactory.java:97)
at com.atlassian.confluence.util.AopUtils.createAdvisedProxy(AopUtils.java:56)
at com.atlassian.confluence.cache.TransactionalCacheFactory.proxyCacheWithUpdateLogging(TransactionalCacheFactory.java:103)
at com.atlassian.confluence.cache.TransactionalCacheFactory.getCache(TransactionalCacheFactory.java:69)
at com.atlassian.confluence.setup.bandana.ConfluenceCachingBandanaPersister.getCache(ConfluenceCachingBandanaPersister.java:41)
at com.atlassian.confluence.setup.bandana.ConfluenceCachingBandanaPersister.retrieve(ConfluenceCachingBandanaPersister.java:54)
at com.atlassian.bandana.DefaultBandanaManager.getValue(DefaultBandanaManager.java:41)
at com.atlassian.bandana.DefaultBandanaManager.getValue(DefaultBandanaManager.java:33)
at com.atlassian.confluence.setup.settings.DefaultSettingsManager.getGlobalSettings(DefaultSettingsManager.java:30)
at com.atlassian.confluence.setup.webwork.AntiXssSettingBasedCartridgeProcessor.isAntiXssModeEnabled(AntiXssSettingBasedCartridgeProcessor.java:35)
at com.atlassian.confluence.setup.webwork.AntiXssSettingBasedCartridgeProcessor.processCartridge(AntiXssSettingBasedCartridgeProcessor.java:25)
at com.atlassian.confluence.setup.webwork.ConfluenceVelocityManager.processContextForRendering(ConfluenceVelocityManager.java:57)
at com.atlassian.confluence.util.velocity.VelocityUtils.renderTemplateWithoutSwallowingErrors(VelocityUtils.java:59)
at com.atlassian.confluence.util.velocity.VelocityUtils.renderTemplateWithoutSwallowingErrors(VelocityUtils.java:66)
at com.atlassian.confluence.util.velocity.VelocityUtils.getRenderedTemplateWithoutSwallowingErrors(VelocityUtils.java:53)
at com.atlassian.confluence.util.velocity.VelocityUtils.getRenderedTemplate(VelocityUtils.java:36)
at com.atlassian.confluence.util.velocity.VelocityUtils.getRenderedTemplate(VelocityUtils.java:29)
at com.atlassian.confluence.extra.dynamictasklist2.TaskListServlet$AddTaskAction.execute(TaskListServlet.java:440)
at com.atlassian.confluence.extra.dynamictasklist2.TaskListServlet.doPost(TaskListServlet.java:116)